Marine propulsion and steering system



Sept. 15, 1964 MARINE W. F. HORNING PROPULSION AND STEERING SYSTEM FiledApril 30, 1962 Wyn/r012,

United States Patent 3,148,657 MARINE PRQPULSEQN AND STEERING SYSTEMWayne F. Homing, Arcadia, Qaliii, assignor to Inboard Marine, inc,Temple City, Calif., a corporation of California Filed Apr. 39, 1962,Ser. No. 1%,935 14 Claims. (Cl. 11535) This invention relates to amarine propulsion and steering system and, more particularly, isdirected to an improved inboard-outboard engine. A conventional inboardengine is located forward and uses a fixed propeller in combination witha rudder for steering. In comparison with an outboard engine, aconventional inboard engine has the disadvantages of steering with wideturns and of requiring constant perfect shaft alignment to avoidexcessive vibration. An inboard engine does, however, offer theadvantage of convenient and safe accessibility, optimum weight location,minimum vulnerability to collision and docking damage, minimumlikelihood of fishing line entanglement, holding a trim more easily,less sensitivity to waves and wind, ability to carry more freeboard orheight at the stern, ability to drive more tonnage at high speed, and,finally, fuel economy. While a conventional outboard engine, on theother hand, lacks these numerous advantages, it has the importantadvantages of ability to turn in small circles for bettermaneuverability and of being more easily installed on a boat.

To combine the advantages of these two conventional types, variousinboard-outboard engines have been developed, each of which comprises aninboard engine with an outboard-style propeller drive system that isrotatable for eflicient short radius steering by propeller thrust. It ischaracteristic of the prevailing types of inboard-outboard engines thatthe drive shaft extends through the transom and is geared to a seconddownwardly extending drive shaft in a rotatable outboard housing.

One problem encountered in constructing such an inboard-outboard engineis to achieve simplicity and struc tural economy, the usual arrangementbeing of complicated costly construction. One reason for thecomplications that characterize the usual arrangement is that theoutboard housing is subject to a heavy torque in reaction to the powerdelivered through the downwardly extending drive shaft, and if theoutboard housing is rotatable for steering, this reaction torqueseriously affects the steering by creating excessively hard steering inone direction and excessively soft steering in the opposite direction.

The present invention is directed primarily to the solution of these twoproblems, i.e. the problem of providing a simple relatively inexpensiverotatable outboard driving unit, and the problem of making such arotatable unit as steerable and free from torque interference as aconventional outboard engine.

With reference to structural simplicity and economy, a feature of theinvention is the concept of mounting an inboard engine in position withits drive shaft extending substantially vertically downward through anopening in the bottom of the boat. The drive shaft extends into adownwardly extending outboard housing under the boat that carries thepropeller and is mounted in the bottom opening of the boat in a rotarymanner for steering by propeller thrust. This lower outboard housing hasan extensive upward extension that telescopes into a similar cylindricalextension of the engine to insure and maintain accurate alignment of thedrive shaft and to form a rotary joint with the engine. In addition thewhole assembly of engine and outboard drive may be tilted adjustablyabout the bottom opening of the boat as a fulcrum for optimuminclination of the propeller axis relative to the boat.

The invention makes a new approach to the problem of reaction torque anddoes so with important advantages. Instead of ignoring the torquereaction of the outboard housing or of seeking defensively to divert orneutralize the reaction torque, the invention takes advantage of thereaction torque by using it for power steering in one direction. Forthis purpose the invention provides a second opposed force for powersteering in the opposite direction. Thus steering in the one directionis at least facilitated in a controlled manner by the reaction torque ofthe outboard housing and steering in the opposite direction is at leastfacilitated by controlled domination over the reaction torque by thesecond opposed force. The term at least facilitated is employed becausewithin the scope of the invention the two opposed forces for powersteering may be of minor magnitude with the steering accomplishedlargely by manual force, the two opposed forces merely facilitatingmanual steering or, on the other hand, the two opposed forces may be ofrelatively large magnitude, the applied manual force being used merelyto trigger the two opposed power steering forces.

A feature of the preferred practice of the invention is that thehelmsman may utilize the two opposed forces to selected degrees asdetermined by the manner in which he manipulates the steering control. Afurther feature is that the steeling control is fail-safe inasmuch asoverriding manual control is always available.

These desirable features are provided by employingfluid-pressure-actuated means, either hydraulic or pneumatic, todominate the torque reaction for changes in one steering direction andby employing a controlled dashpot means, either hydraulic or pneumatic,to yield to the torque reaction for changes in the opposite steeringdirection. In the preferred practice of the invention, the steeringsystem is hydraulic and a single hydraulic chamber is employed both aspower means to dominate the reaction torque and as dashpot means orfluid-metering means to retard the steering effect of the reactiontorque.

To carry out this concept, a manually operable control member is movablymounted on the outboard housing for movement relative thereto in thetwoopposite steering directions and this control member has a neutralposition between two normally closed valves that are fixedly mountedrelative to the outboard housing. Manual movement of the control memberin one direction opens the corresponding valve to admit fiuid to thepower chamber to overcome the reaction torque for steering in the onedirection. Manual movement of the control member in the oppositedirection opens the other valve to release fluid from the power chamberin a controlled dashpot manner to permit the reaction torque to steer inthe op posite direction.

The preferred practice of the invention is further characterized by theuse of spring means to urge the control member to its neutral positionat which it affects neither of the two normally closed valves. sity ofproviding special spring means for this purpose is avoided simply byusing normally closed spring-loaded Patented Sept. 15, 1964 In practice,the neces 2 as valves. Manual movement of the control member relative tothe outboard housing in either steering direction overcomes the springpressure and progressively opens the corresponding valve. The advantageof this arrangement is that it gives the helmsman a certain feel orperception of rudder resistance that simulates the characteristicresistance of an actual rudder and thus not only promotes maneuveringskill but also adds to the pleasure of navigation.

It is further apparent that the arrangement affords choice over a widerange in the degree of power assistance to steering. At one extreme themanual steering force is relatively light, being merely sufficient toopen the appropriate valve, the magnitude of the released power and therate of steering change being determined by the degree to which thevalve is opened. At the other extreme, manual steering force may beapplied vigorously and abruptly to serve as the dominating steeringforce.

The use of hydraulic means both for overcoming the reaction torque forsteering in one direction and for controlling the utilization of thereaction torque for steering in the opposite direction has theunexpected advantage of providing a hydraulic lock for automaticallyholding any selected steering adjacent of the rotatable outboardhousing. Thus if the operator releases the manual control or lets thespring resistance determine the position of the manual control, themanual control seeks its neutral position automatically at whichposition both of the two valves are closed to trap the hydraulic fluidin the power chamber.

Simplicity and structural economy are further achieved by utilizing thelubrication system of the engine itself to avoid the necessity ofproviding a special pump or the like for feeding pressurized fluid tothe power steering chamber. For this purpose the normally closed inletvalve for the power chamber is connected to the oil pump or highpressure region of the lubrication system and the normally closed outletvalve for the power chamber is connected to the sump or low pressureregion of the lubrication system. The temperature of the lubricantvaries widely with different operating conditions with correspondingwide changes in the viscosity of the hydraulic fluid, but the changes inviscosity, merely require corresponding changes in the degrees to whichthe two valves must be opened for given steering effects.

The features and advantages of the invention may be understood from thefollowing detailed description and the accompanying drawing.

In the drawing, which is to be regarded as merely illustrative:

FIG. 1 is a fragmentary view partly in elevation and partly in sectionshowing an installation of the presently preferred embodiment of theinvention; and

FIG. 2 is a view that is partly diagrammatic and partly in section, thesection being taken along the line 2-2 of FIG. 1 and the diagramindicating the construction of the hydraulic system.

In FIG. 1 of the drawing illustrating the selected embodiment of theinvention, an inboard engine, generally designated 10, is mounted insidea boat generally designated 12, which boat has a circular bottom opening14. The inboard engine is mounted and braced above the opening 14 withthe drive shaft 15 of the engine extending downward through the bottomopening into an outboard housing, generally designated by the numeral16, the outboard housing carrying a propeller 18 on a transversepropeller shaft 20. In a well-known manner, an upper beveled gear 22 anda lower beveled gear 24, both freely rotatable on the drive shaft 15,mesh with a third beveled gear 25 that is fixedly mounted on thepropeller shaft 20. A conventional ratchet collar 26 that is slidinglykeyed to the drive shaft 15 is movable selectively into engagement withthe two beveled gears 22 and 24 to key the two beveled gears selectivelyto the drive shaft 15 for rotating the propeller 18 selectively inopposite directions, the ratched collar being controlled in a wellknownmanner by a manually operated push-pull control rod 28.

In the construction shown, the engine 10 has a down- Ward cylindricalextension 30, the lower end of which is formed with a convex sphericallycurved rim 32 that seats adjustably in a similarly curved bearing plate34 that surrounds the bottom opening 14. It is apparent that thisconstruction provides a ball-type universal joint which permits theengine 10 to be tilted adjustably about the opening 14 as a fulcrum.Thus the engine may be tilted to adjust the angle of inclination of thepropeller shaft 20 relative to the boat.

The outboard housing 16 has an axial tubular extension 35 whichrotatably telescopes into the cylindrical extension 33 of the engine 10,the tubular extension being suitably held against axial movementrelative to the cylindrical extension of the engine and being sealedwith respect to the cylindrical extension by suitable sealing means. Theouter cylindrical extension 30 of the engine has a circumferentiallyextending slot 36 and a rigid arm 38 of the inner tubular extension 35extends radially outward through the slot to control the rotary positionof the outboard housing 16. The rigid arm 38 may be in the form of asubstantially horizontal metal plate, as shown.

Assuming that the reaction torque transmitted to the outboard housing 16by the drive shaft 15 is counterclockwise as viewed in FIG. 2, asuitable hydraulic means is connected to the arm 38 to oppose thecounterclockwise rotation, the hydraulic means comprising a singleacting cylinder 40 that is connected to the arm by a pivot 42. A piston44 in the cylinder 40 has a piston rod 45 which is pivotally connectedto a fixed portion 46 of the boat by a suitable pivot 48. The cylinder40 forms a power chamber 50 with a single port which is connected by aflexible hose 52 to an inlet valve 54 and is connected by a secondflexible hose 55 to an outlet valve 56.

The two valves 54 and 56 are fixedly mounted on the arm 38 on theopposite sides of a manually operable control member 58, the controlmember being mounted on the arm 38 by a pivot 60 to swing relative tothe arm 38 in the two opposite steering directions. The two valves 54and 56 are spring-loaded normally closed valves having operatingplungers 62 which are directed towards the control member 58 on oppositesides of the control member. The usual springs incorporated in the twovalves 54 and 56 to urge the valve to closed positions serve toyieldingly urge the two operating plungers 62 to their outermostpositions whereby the two plungers cooperate in a yielding manner tourge the control member towards its normal position shown in FIG. 2.

It is apparent that if the control member 58 is rotated clockwiserelative to the arm 38 about the pivot 60, the control member depressesthe plunger 62 of the inlet valve 54 to open the inlet valve foradmitting hydraulic fluid under pressure to the power chamber 50 tocause the power chamber to move the arm 38 and the outboard housing 16clockwise about the axis of the drive shaft 15. On the other hand, ifthe control member 58 is swung counter-clockwise about the pivot 60relative to the arm 38, the control member depresses the plunger of theoutlet valve 56 to release fluid from the power chamber 50, the fluidbeing expelled with retarding dashpot effect by the reaction torqu ofthe outboard housing 16. Two stops 78 are provided on the arm 38 onopposite sides of a control member 53 to limit the swinging movement ofthe control member against the operating plungers of the two valves 54and 56.

The two valves 54 and 56 are connected to the lubrication system of theengine 10. As indicated diagrammatically in FIG. 2, the lubricationsystem of the engine has a low pressure region which includes a sump 64and a fluid passage 65 connected to the intake side of an oil pump 66through a filter 68. The output side of the oil pump 66 in the highpressure region of the lubrication system is connected to a fluidpassage 70 which distributes the lubricant to various parts of theengine. The inlet valve 54 of the hydraulic steering system is connectedby a flexible hose '72 to the high pressure region of the lubricationsystem, i.e. to the pump through the pipe 70 and the outlet valve 56 isconnected by a flexible hose 73 to the low pressure region of thelubrication system, i.e. to the sump 64 through the pipe 65.

The pivoted control member 58 may serve as a tiller and may be providedwith a handle for this purpose. In this particular embodiment of theinvention, however, the operating member 58 is connected by a pair ofopposed cables 74 to a remote wheel (not shown) in a wellknown manner,the opposed cables being routed to the remote wheel by suitable guidepulleys including two guide pulleys 7 5.

The manner in which the invention serves its purpose may be readilyunderstood from the foregoing description. It is apparent that thecontrol member 58 normally seeks its neutral position since any swingingmovement out of its neutral position is opposed by the spring action ofthe two normally closed valves 54 and 56. When the control member 58 isin its normal neutral position, both of the valves 54 and 56 are closedto trap the fluid in the power chamber whereby the power chamber servesas a hydraulic lock to maintain the outboard housing 16 at whateversteering position it may be adjusted.

If the control member 58 is turned clockwise as viewed in FIG. 2 by theremote wheel acting through one of the cables 74, the inlet valve 54 isopened to admit the high pressure lubricant to the power chamber 50whereupon the power chamber 5i overcomes the reaction torque of theoutboard housing 16 to swing the outboard housing clockwise. On theother hand if the remote wheel swings the control member 58counter-clockwise out of its neutral position, the outlet valve 56 opensto release the fluid from the power cylinder 50 to permit the reactiontorque of the outboard housing 16 to rotate the outboard housingcounter-clockwise, the counterclockwise movement being retarded by thedashpot action involved in the expelling of fluid from the powerchamber. In this dashpot action the outlet valve 56 functions as avariable orifice for varying the resistance to the fluid discharge. Ifdesired, an orifice fitting '76 may be inserted in the flexible hose 73to serve as a limiting orifice.

It is apparent that if the control member 58 is swung forcibly againsteither of the two stops '78 the manual force will be transmitteddirectly to the arm 38 and the consequent steering movement will belargely manually operated. On the other hand, if the applied manualforce is insuflicient to cause the control member 58 to move against oneof the stops 78, the steering movement of the outboard housing is poweractuated except for the manual force indirectly transmitted by thesprings of the two valves. It is the spring resistance of the two valvesthat gives the helmsman the desired rudder feel. In the event that thepower steering system fails, overriding manual force may be used tosteer the outboard housing.

My description in specific detail of the selected embodiment of theinvention will suggest various changes, substitutions and otherdepartures from my invention within the spirit and scope of the appendedclaims.

I claim:

1. In an outboard drive for a boat having an inboard engine, thecombination of:

an outboard housing extending from the boat;

a propeller carried by said housing to drive the boat, said housingbeing rotatable relative to the boat to vary the orientation of thepropeller relative to the boat for steering the boat by the thrust ofthe propeller;

transmission means extending from the engine downward through saidhousing to drive said propeller with consequent reaction torque on thehousing tending to turn the housing in one steering direction; and

a single remotely controlled fluid-pressure-actuated ram connected tosaid housing eccentrically thereof to oppose said reaction torque toturn the housing in the other steering direction and to yield to saidreaction torque with a dashpot action to permit the reaction torquealone to turn said housing in said one steering direction.

2. A combination as set forth in claim 1 in which saidfluid-pressure-actuated means includes normally closed valve means totrap fluid in the ram to lock said housing against rotation in said onesteering direction.

3. In an outboard drive for a boat having an inboard engine wherein theengine has a lubrication system with a low pressure region and a highpressure region, the combination of:

an outboard housing extending from the hull of the boat;

a propeller carried by said housing to drive the boat, said housingbeing rotatable to vary the orientation of the propeller relative to theboat for steering the boat by the thrust of the propeller;

transmission means extending from the engine through said housing todrive said propeller with consequent reaction torque on the housingtending to turn the housing in one steering direction;

a single hydraulic means operatively connected to said housing to exertforce in a single direction to oppose said reaction torque; and

control means operable in one respect to cut off the hydraulic meansfrom said low pressure region of the lubrication system and to place thehydraulic means in communication with the high pressure region toreceive lubricant therefrom to overcome said reaction torque for turningsaid housing in the opposite steering direction, said control meansbeing operable in the opposite respect to cut off the hydraulic meansfrom the high pressure region and to place the hydraulic means incommunication with the low pressure region for metered return of thelubricant to the lubrication system to permit the reaction torque toturn the housing in said one steering direction.

4. A combination as set forth in claim 3 in which said control means isoperable in a third respect to cut off the hydraulic means from thelubrication system for hydraulically locking said housing againstrotation at selected steering positions of the housing.

5. In an outboard drive for a boat having an inboard engine, thecombination of:

an outboard housing extending downward from the boat;

a propeller carried by said housing to drive the boat, said housingbeing rotatable relative to the boat to steer the boat by the thrust ofthe propeller;

transmission means extending from the engine through said housing todrive said propeller with consequent reaction torque on the housingtending to turn the housing in one steering direction;

control means connected to said housing and movable relative thereto inthe two opposite steering directions of the housing;

a fluid-pressure-actuated system operatively connected to said housingand including a power chamber for expansion to turn said housing in theopposite steering direction;

a normally closed inlet valve in said system to admit pressurized fluidto said power chamber to overcome said reaction torque to turn saidhousing in the opposite steering direction, said inlet valve beingmounted on one of said housing and control means for opening operationby the other of said housing and control means in response to movementof the control means relative to the housing in said opposite steeringdirection; and

a normally closed outlet valve in said system to release fluid from saidpower chamber to permit said reaction torque to turn the housing in saidone direction at a rate retarded by the frictional resistance to flow ofthe released fluid, said outlet valve being mounted on one of saidhousing and control means for opening operation by the other of saidhousing and control means in response to movement of the control meansrelative to the housing in said one steering direction.

6. A combination as set forth in claim 5 in which said control means hasfreedom to take a neutral position at which both of the two valves areclosed to trap fluid in the power chamber to lock the housing againstrotation at selected steering positions of the housing.

7. A combination as set forth in claim 6 which includes yielding meansacting between the housing and the control means to yieldingly urge saidcontrol means towards its neutral position.

8. In an outboard drive for a boat having an inboard engine, thecombination of:

an outboard housing extending downward from the boat;

a propeller carried by said housing to drive the boat, said housingbeing rotatable relative to the boat to steer the boat by the thrust ofthe propeller;

transmission means extending from the engine through said housing todrive said propeller with consequent reaction torque on the housingtending to turn the housing in one steering direction;

a control means connected to said housing and movable relative theretofrom a neutral position in the two opposite steering directions of thehousing;

a fluid-pressure-actuated system connected to said housing and includinga power chamber for expansion to turn said housing in the oppositesteering direction;

an inlet valve in said system to admit pressurized fluid to said powerchamber to overcome said reaction torque to turn said housing in theopposite steering direction, said inlet valve being mounted on one ofsaid housing and control means for opening operation by the other ofsaid housing and control means in response to movement of the controlmeans relative to the housing in said opposite steering direction;

an outlet valve in said system to release fluid from said power chamberto permit said reaction torque to turn the housing in said one directionat a rate retarded by the frictional resistance to flow of the releasedfluid, said outlet valve being mounted on one of said housing andcontrol means for opening operation by the other of said housing andcontrol means in response to movement of the control means relative tothe housing in said one steering direction; and

yielding means to urge both of said valves to their closed positionthereby to urge said control means to its neutral position.

9. In an outboard drive for a boat having an inboard engine wherein theengine has a lubrication system with a low pressure region and a highpressure region, the combination of a control means connected to saidhousing and movable relative thereto in the two opposite steeringdirections of the housing;

a fluid-pressure-actuated system operatively connected to said housingand including a power chamber for expansion to turn said housing in theopposite steering direction;

a normally closed inlet valve included in said fluidpressure-actuatedsystem to place said power chamber in communication with said highpressure region to admit pressurized lubricant to the power chamber toovercome said reaction torque to turn said housing in the oppositesteering direction, said inlet valve being mounted on one of saidhousing and control means for opening operation by the other of saidhousing and control means in response to move ment of the control meansrelative to the housing in said opposite steering direction; and

a normally closed outlet valve included in said system to releaselubricant from said power chamber to said low pressure region to permitsaid reaction torque to turn the housing in said one direction at a rateretarded by the frictional resistance to flow of the released lubricant,said outlet valve being mounted on one of said housing and control meansfor opening operation by the other of said housing and control means inresponse to movement of the control means relative to the housing insaid one steering direction.

10. A combination as set forth in claim 9 in which said control means ismovable to a neutral position at which both of said valves are closedand which includes spring means to oppose movement of the control meansout of its neutral position.

11. In a system for propelling and guiding a boat, the combination of:

an engine insidethe boat;

an opening in the bottom of the boat;

an outboard housing extending downward from said opening, said housingbeing connected with the opening in a fluid-tight manner, and beingrotatable relative to the opening;

a propeller carried by said housing for rotation on an axis extendinglaterally of the axis of rotation of the housing for propelling the boatin directions determined by the rotary position of the housing;

means to transmit power from the engine to the propeller including drivemeans extending from the engine through said opening into said housingwhereby the drive means applies a reaction torque to said housing forrotation of the housing in one steering direction; and

a single manually controlled fluid-pressure-actuated means inside theboat connected to the boat and to said housing to exert force in asingle direction to oppose said reaction torque and to yield to saidreaction torque with dashpot action to cause the reaction torque to turnsaid housing in said one steering direction.

12. A combination as set forth in claim 11 in which saidfluid-pressure-actuated means includes normally closed valves to locksaid outboard housing against rotation at selected steering positions ofthe housing.

13. In a system for propelling and guiding a boat, the combination of:

an engine inside the boat, said engine having a lubrication system witha low pressure region and a high pressure region;

an outboard housing extending downward from said opening, said housingbeing connected with the opening in a fluid-tight manner, and beingrotatable relative to the opening;

a propeller carried by said housing for rotation on an extendinglaterally of the axis of rotation of the housing for propelling the boatin directions determined by the rotary position of the housing;

means to transmit power from the engine to the propeller including drivemeans extending from the engine through said opening into said housingwhereby the drive means applies a reaction torque to said housing forrotation of the housing in one steering direction;

hydraulic means inside the boat connected to the boat and to saidhousing to oppose said reaction torque; and

control means operable in one respect from a neutral position to cut offthe hydraulic means from the low pressure region of the lubricationsystem and to place the hydraulic means in communication with the highpressure region to receive lubricant therefrom to overcome said reactiontorque for turning said housing in the opposite steering direction, saidcontrol means being operable in the opposite respect to cut oh thehydraulic means from the high pressure region and to place the hydraulicmeans in communication with the low pressure region for metered returnof the lubricant to the lubrication system to permit the reaction torqueto turn the housing in said one steering direction, said control meansbeing operable in a third respect to out oil the hydraulic means fromboth of said regions of the lubrication system for hydraulically lockingsaid outboard housing against rotation at selected steering positions ofthe outboard housing.

14. A combination as set forth in claim 13 which includes yielding meansto oppose operation of said control means out of its neutral position.

References Cited in the file of this patent UNITED STATES PATENTS

1. IN AN OUTBOARD DRIVE FOR A BOAT HAVING AN INBOARD ENGINE, THECOMBINATION OF: AN OUTBOARD HOUSING EXTENDING FROM THE BOAT; A PROPELLERCARRIED BY SAID HOUSING TO DRIVE THE BOAT, SAID HOUSING BEING ROTATABLERELATIVE TO THE BOAT TO VARY THE ORIENTATION OF THE PROPELLER RELATIVETO THE BOAT FOR STEERING THE BOAT BY THE THRUST OF THE PROPELLER;TRANSMISSION MEANS EXTENDING FROM THE ENGINE DOWNWARD THROUGH SAIDHOUSING TO DRIVE SAID PROPELLER WITH CONSEQUENT REACTION TORQUE ON THEHOUSING TENDING TO TURN THE HOUSING IN ONE STEERING DIRECTION; AND ASINGLE REMOTELY CONTROLLED FLUID-PRESSURE-ACTUATED RAM CONNECTED TO SAIDHOUSING ECCENTRICALLY THEREOF TO OPPOSE SAID REACTION TORQUE TO TURN THEHOUSING IN THE OTHER STEERING DIRECTION AND TO YIELD TO SAID REACTIONTORQUE WITH A DASHPOT ACTION TO PERMIT THE REACTION TORQUE ALONE TO TURNSAID HOUSING IN SAID ONE STEERING DIRECTION.